Conclusion: The alcohol extracts of Senecio scandens Buch-Ham. have obvious anti-inflammatory analgesic effect, and has a certain peripheral analgesic activity, its anti-inflammatory effects may be related to its inhibition of PGE2 synthesis or release from inflammatory tissue.

Keywords

Senecio, Anti-inflammatory, Analgesia, Mechanism of action

Introduction

Senecio scandens Buch-Ham. (SSBH) is one of commonly
used traditional Chinese medicine in China [1]. The historical
records named Gleaning Herb recorded its properties anti-inflammatory
and antiallergenic [2]. It was mainly distributed
in Zhejiang, Jiangsu, Anhui and other places. Its
pharmacological activities including heat-clearing and
detoxifying, improving eyesight, cooling blood, expelling wind
and removing damness [3-5]. The extracts could be mainly
classified into several categories of flavonoids, phenolic acids,
volatile oils, alkaloids, etc [6]. Researchers reported that the
decoction has obvious inhibition on many bacteria like Staphylococcus aureus, Diphtheria bacillus, Salmonella typhi,
Escherichia coli, proteus and Dysentery bacillus [2,3]. More
importantly, it could protect the liver from its lesion by inhibit
the levels of ALT and AST in serum [7]. We therefore designed
this study to observe the anti-inflammatory and analgesic
effects of the Senecio scandens Buch-Ham. ethanol extracts.

Materials and Methods

Extracts preparation

SSBH was collected from Henan Province Hao Xin Chinese
medicinal materials co., LTD., verified by the College of
Traditional Chinese Medicine of university. 4 kg of this
medicine was extracted for three times with 95% ethanol, and
got 748 g extracts by the method of low vacuum drying. 150 g
extracts were used to the studies of the anti-inflammatory and
analgesic effects. Ibuprofen Sustained Release Capsules
(Tianjin schick pharmaceutical co., LTD of China and the
United States) Pethidine hydrochloride injection (Northeast
pharmaceutical group shenyang first pharmaceutical co., LTD)

Methods

Fifty Kunming mice were randomly divided into 5 groups,
including blank, ibuprofen group, alcohol extract of SSBH
high, medium and low dose group (the equivalent of 3.0, 1.5,
0.75 g/kg). Administered by intragastric administration (ig)
consecutively for 7 days, as for blank group, was given the
same amount of 0.5% sodium carboxymethyl cellulose
solution. Intraperitoneal injection was given at the last
administration with 0.01 ml/g (0.7%). Record mice body
torsion times within 10 minutes, extend hind legs, concave
abdomen, hip elevation, calculate the rate of analgesia.

Fifty female KunMing mice were put on the hot plate (55 ±
0.2), record the required reaction time of licking enough, the
pain response latency as the pain threshold of mice, select fifty
mice whose pain threshold range from 5 to 30, including blank,
ibuprofen group, alcohol extract of SSBH high, medium and
low dose group (the equivalent of 3.0, 1.5, 0.75 g/kg). And
then every mouse was put on one by one on the hot plate
instrument, got the determination of drug delivery of pain
threshold twice, take the average value as the medicine before
the pain threshold. Administered by intragastric administration
(ig) consecutively for 7 days, as for blank group, was given the
same amount of 0.5% sodium carboxymethyl cellulose
solution. Record the pain threshold of mice 30 mins after the
last administration, and calculate the pain threshold percentage
increase.

Fifty female KunMing mice were grouped and divided
randomly, including blank, ibuprofen group, alcohol extract of
SSBH high, medium and low dose group (the equivalent of
3.0, 1.5, 0.75 g/kg). Administered by intragastric
administration (ig) consecutively for 7 days, as for blank
group, was given the same amount of 0.5% sodium
carboxymethyl cellulose solution. 30 mins later, Xylene was
dropped on the left auricle of mice (20 μl), and 1 hour later, the
mice were ultimately killed, cut around the ears to punch 8 mm
of diameter respectively in the same place. Each mice was
weighed by the analytical balance, the ear swelling degree and
the inhibition rate were calculated.

Fifty male SD rats were grouped and divided randomly,
including blank, ibuprofen group, alcohol extract of SSBH
high, medium and low dose group (the equivalent of 3.0, 1.5,
0.75 g/kg). All the mice were given the same medicine as
mentioned above. Before the last delivery, water displacement
of the right rear foot of the researched rats was tested. And
after I.g. administration, the right hind paw of every SD rats
were hypodermic injected with 0.1 ml 10% egg white. The
water displacement was recorded at 1, 2, 3, 5, 6h. The swelling rate differences was swelling volume, calculate the swelling
rate, and observes the peak time and fade time, at last the
differences were compared between the treatment group and
blank group.

Thirty male SD rats were grouped and divided randomly to
five groups as mentioned above. Every rat was light
anesthetized, and under the sterile condition, the cotton ball
(each weighed 30 mg ± 0.5 mg, high pressure sterilization, and
contained 1 mg/0.1 ml, dried at 50) was implanted in the rat
groin skin on both sides. Administered at the onset of surgery
by intragastric administration (ig) consecutively for 7 days. As
for blank group, was given the same amount of 0.5% sodium
carboxymethyl cellulose solution. The rats were ultimately
killed and the cotton balls were got out and were placed in
oven at 60 for 12 hours. The weight of granuloma was
calculated out with the difference between the weight of before
and after the test.

Effect of SSBHE on the PGE2 in the excretions of rat
with paw edema [13]

During this test, after the detection of feet swelling degrees,
the rats were killed. Cut out the inflammatory foot ankle and
peeled, cut up into 2 ml saline soak for 24 h, centrifuged, 2 ml
methanol solution of potassium hydroxide was added to 0.1 ml
supernatant liquid. Diluted with methanol to 4 ml, OD value
was tested at 278 nm, per gram inflammation tissue equivalent
OD value (A/g) showed the content of PGE2.

Effect of SSBHE on the in mice analgesia experiment
induced by formaldehyde [14]

Sixty male mice were grouped and divided randomly,
including blank, ibuprofen group, alcohol extract of SSBH
high, medium and low dose group (the equivalent of 3.0, 1.5,
0.75 g/kg) and pethidine group. The first five groups were all
administered as the Twisting test in Kunming mice caused by
acetic acid, 6 groups of intraperitoneal injection of pethidine
(1.5 mg/kg). The first group were all given pethidine by
intraperitoneal injection (1.5 mg/kg). After one hour, 10 μl
formalin solution (2.5%) were subcutaneous injected
consecutively. Observe the accumulated time of pain reaction
in mice after ten minutes and twenty minutes, then were rated.
Grading methods: licking, biting or shake foot got 3 points,
raise foot got two points, claudication and foot hold with freely
about 0. Calculate the cumulative score at phase I and II,
cumulative score = (0t1 +1t2 +2t3 +3t4)/(t1 +t2 +t3 +t4)
[ t1t2t3t4 were the duration at the score of 0,1,2,3]

Results

Twisting in Kunming mice caused by acetic acid

Compared with blank group, ibuprofen group and SSBHE
could significantly inhibit the twisting induced by acetic acid.
In addition, the inhibition showed a concentration-response relationship. This result suggested that the SSBHE could
obviously inhibit the pain caused by chemical stimulation. The
results showed in Table 1.

Compared with pre-administration and blank group, the
incubation period of mice on the hot plate could be slightly
extended by high dose of SSBHE, but middle dose and low
dose could not exhibit great effect, as showed in Table 2.

Table 3: The effects of SSBHE on the test of mice ear swelling induced
by xylene (± s, n=10).

Effect of SSBHE on the albumin induced rat paw
edema test

Each dose mentioned in this study could all inhibit the edema
induced by egg white, and exhibits a concentration-efficiency
relationship, suggested that SSBHE has a good anti-inflammatory
effect, showed in Table 4.

Table 5: The effects of SSBHE on the test of cotton induced granuloma
in rats (± s, n=10).

Effect of SSBHE on the PGE2 in the excretions of rat
with paw edema

Each dose of SSBHE could obviously decrease the content of
PGE2 in the excretions of paw edema, suggested that SSBHE may could suppress the synthesis or release of PGE2 to show
the anti-inflammatory activity, showed in Table 6.

Table 6: Effect of SSBHE on the PGE2 in the excretions of rat with paw edema (± s,
n=10).

Effect of SSBHE on the in mice analgesia experiment
induced by formaldehyde

The effect of SSBHE on first phase was not obvious, but could
significantly inhibit the second phase, suggested that it has a
good analgesic effect on the pain induced by peripheral
sensitization (Table 7).

Discussion

This research had proved that the ethanol extracts of Senecio scandens Buch-Ham. (SSBHE) has obvious anti-inflammatory
and analgesic pharmacological effects, actually this two
activity were also related with its excellent antibacterial
activity closely. SSBHE contains many flavonoids, including
Hyperoside, linarin and other same kinds [15]. Meanwhile, it
could exhibit a great inhibition on the Staphylococcus aureus,
Salmonella enteritidis, Bacillus anthracis [2,3].

Both of hot plate test and acetic acid body torsion experiment
were used to study the analgesic effect of SSBHE. However,
there are differences between the above two methods. The hot
plate method is suitable for evaluation of the effect of high
pericranium participated in, but acetic acid body torsion
experiment was suitable for peripheral analgesic mechanism
research. Results showed that SSBHE had peripheral analgesic
activity, but central analgesic activity was not obvious. The
formalin test in mice was internationally recognized for
screening of weak analgesic drugs. As for this model, the pain
response was classified into two phases, which represent
different types of pain, the first phase was a direct pain effect
on nerve endings, and however the second phase was generated
by peripheral nerve stimulation. Results show that the SSBHE
could significantly weaken the pain at the second phase, but
SSBHE showed few effect on the pain reaction, suggested that
the it has certain peripheral analgesic activity. This was in line
with the results of the hot plate test and the acetic acid twisting
test, all the results got in this study clarify commendably
analgesic mechanism of SSBHE.

PEG2 is one of a very important inflammatory mediator, exists
in inflammatory tissue, synergy was played after its interaction
with bradykinin and leukotrienes. Then, vasodilation and
vascular permeability were all increased, at last the synthesis of
PEG2 was inhibited, therefore the inflammatory reaction was
remitted. The results of this study showed that the anti-inflammatory
effects may be related to the two reduction of the
PEG2 content in the inflammatory tissue, the analgesic effect
also might be related to the synthesis and release of PEG2
content in the inflammatory tissue. In addition, PEG2 also was
a kind of important medium pain and peripheral pain could be
caused by PEG2 was already clear to us.